Elucidating the Benefit of Perforated vs Non-Perforated Membranes in Guided Bone Regeneration: An in Vivo Histologic Evaluation and Histomorphometric Analysis.

Background: Non-perforated Polytetrafluoroethylene (PTFE) membranes are effectively utilized in guided bone regeneration (GBR) but may hinder cell migration due to limited interaction with the periosteum. This study compared bone regeneration using occlusive or perforated membranes combined with acellular collagen sponge (ACS) and recombinant human bone morphogenic protein-2 (rhBMP-2) in a canine mandibular model. Material and Methods: Male beagle dogs (n=3) received two mandibular defects each to compare ACS/rhBMP-2 with experimental (perforated group) and control (non-perforated group) membranes (n=3 defects/group). Tissue healing was assessed histomorphologically, histomorphometrically and through volumetric reconstruction using microcomputed tomography. Results: The perforated group showed increased bone formation and reduced soft tissue formation compared to the non-perforated group. For the primary outcome, histomorphometric analysis revealed significantly greater total regenerated bone in the perforated group (67.08 ± 6.86%) relative to the nonperforated group (25.18 ± 22.44%) (p = 0.036). Perforated membranes had less soft tissue infiltration (32.91 ± 6.86%) compared to non-perforated membranes (74.82 ± 22.44%) (p = 0.036). Conclusion: The increased permeability of membranes in the perforated group potentially enabled periosteal precursor cells greater accessibility to rhBMP-2. The availability may have accelerated their differentiation into mature bone-forming cells, contributing to the stimulation of new bone production, relative to the non-perforated group.

Decision Tree for Reconstructive Treatment of Peri-implantitis Defects.

Peri-implantitis, a common complication among patients receiving implant-supported restorative therapy, often requires surgical intervention for effective treatment. Understanding the specific configuration of peri-implant bony defect and adjacent bone peaks is crucial for tailoring treatment strategies and improving outcomes. A decision tree for reconstructive peri-implantitis therapy has been developed based on the new classification of defect configurations (Class I to V), guiding clinicians in selecting treatment options, including biomaterials, techniques, and healing approaches. Furthermore, clinicians are encouraged to consider various factors such as local predisposing factors (such as soft tissue characteristics, prosthetic design, and implant position in three-dimensional perspective), clinical factors (surgeon skill and experience), and patient-related factors (such as local and systemic health, preferences, and cost) when evaluating reconstructive therapy options.

The adjunctive effect of polydeoxyribonucleotide on bone formation in alveolar ridge preservation: A pre-clinical in vivo study.

AIM: This study investigated the adjunctive effect of polydeoxyribonucleotide (PDRN) on bone formation in alveolar ridge preservation (ARP) sockets. MATERIALS AND METHODS: Both mandibular second, third and fourth premolars of eight beagle dogs were randomly divided into ARP and ARP/PDRN groups. Following tooth extraction, ARP procedures were conducted using collagenized alloplastic graft material and bilayer collagen membrane soaked with normal saline (ARP group) or PDRN (ARP/PDRN group) for 10 min before application. Both groups were also randomly allocated to 2-, 4- or 12-week healing subgroups. The primary endpoint of this study was to compare histomorphometric differences between ARP and ARP/PDRN. The secondary endpoints of this study were to compare micro-CT analysis and three-dimensional volumetric measurement between the two groups. RESULTS: In the histomorphometric analysis, the ARP/PDRN group exhibited greater new bone formation at coronal, middle and total position compared with the ARP group at 2-week healing. The number of newly formed blood vessels was higher in the ARP/PDRN group than in the ARP group at 2- and 4-week healing. In micro-CT analysis, the mean new bone volume/total bone volume between ARP and ARP/PDRN was statistically significant at 2-week healing. Ridge volume alterations were significantly decreased in the ARP/PDRN group during entire healing time compared with the ARP group, especially on the buccal side. CONCLUSIONS: The application of PDRN in ARP might provide additional benefits for early bone regeneration and maintenance of buccal ridge volume.

Management of the Lingual Flap During Vertical Augmentation of the Atrophic Anterior Mandible: Anatomical Overview and Description of the Technique.

Vertical ridge augmentation in the anterior mandible is a technically delicate procedure that requires knowledge of some anatomical structures to reduce intra- and postoperative complications. Proper soft tissue management is one of the primary aspects to the success of these techniques, enabling tension-free primary wound closure and preventing membrane exposure. This cadaveric and clinical study provides an anatomical overview of the lingual portion of the anterior mandible. Moreover, there is a description of a novel surgical approach for release of the lingual flap that will help clinicians achieve primary closure without incurring intrasurgical complications.

The Clinical Relevance of the Lingual Branch in Ridge Augmentation of the Posterior Mandible: A Pilot Cadaver Study.

Guided bone regeneration (GBR) requires a tension-free flap without damaging the collateral circulation in order to secure better surgical outcomes. Topographic knowledge regarding the neurovascular bundles in the posterior aspect of the mandible can prevent complications during lingual flap design. The lingual branch (LB) of the inferior alveolar or maxillary arteries is not sufficiently illustrated or described in the literature. Nevertheless, it has an intimate relationship with the lingual nerve (LN) during ridge augmentation and implant-related posterior mandible surgery. Therefore, this study aimed to clarify the morphology and topography of the LB related to GBR surgeries. In the present human cadaveric study, the LB was analyzed in 12 hemimandibles using latex injection and corrosion casting. Two types of LB were identified based on their origin and course. The LB was found in a common connective tissue sheath close to the LN. The LB assembled several anastomoses on the posterior lingual aspect of the mandible and retromolar area. The LB acted as an anatomical landmark in identifying LN at the posterior lingual aspect of the mandible.

The influence of vertical ridge augmentation techniques on peri-implant bone loss: A systematic review and meta-analysis.

INTRODUCTION: The primary aim of this systematic review was to investigate and compare the outcomes of different vertical ridge augmentation (VRA) techniques in relation to peri-implant bone loss (PBL), after at least 12 months of functional loading. MATERIAL AND METHODS: The search was conducted to find all the studies about VRA and measurements of PBL with at least 12 months follow-up. Three pairwise meta-analysis (MA) was performed to completely evaluate the outcomes. RESULTS: A total of 42 studies were included, of which 11 were randomized clinical trials (RCTs). RCTs were available only for guided bone regeneration (GBR), onlay, and inlay techniques. The weighted mean estimate (WME) of PBL value was found to be 1.38 mm (95% confidence interval [95% CI]: 1.10-1.66) after a mean follow-up of 41.0 ± 27.8 months. GBR, Inlay, Onlay, osteodistraction, and SBB represented in weight 32.9%, 30.6%, 25.0%, 7.6%, and 3.9%, respectively; and their WME (95% CI) were 1.06 (0.87-1.26) mm, 1.72 (1.00-2.43) mm, 1.31 (0.87-1.75) mm, 1.81 (0.87-1.75) mm, and 0.66 (0.55-0.77) mm, respectively. Among the secondary outcomes, the analysis was conducted for vertical bone gain, healing complication rate, surgical complication rate, implant survival, and success rate. CONCLUSIONS: The primary findings of the meta-analysis, based on the changes between final and baseline values, showed that the peri-implant bone loss could be influenced by the type of intervention but there is a need to evaluate in RCTs the behavior of the peri-implant bone levels after long-term follow-up for all techniques.

Influence of residual pockets on periodontal tooth loss: A retrospective analysis.

BACKGROUND: Individuals enrolled in supportive periodontal therapy (SPT) can still present with tooth loss due to periodontitis (TLP). There is limited evidence on the influence of residual pockets (RPc) and a defined "threshold" at which a patient's profile is set to be at high risk for TLP in the literature. Therefore, this study aimed to assess the influence of RPc on TLP and determine the prognostic performance of RPc compared to the staging and grading of periodontitis on TLP risk. METHODS: Clinical data from 168 patients (3869 teeth) treated for periodontitis and receiving SPT for at least 10 years were evaluated in this retrospective study. TLP and the percentage of sites with RPc ≥ 5 mm or ≥6 mm per patient were collected. The prognostic performance of RPc was compared to the staging and grading of the disease on TLP using a multilevel Cox proportional hazard regression model. RESULTS: Over a median follow-up of 25 years, 13.7% of teeth were lost, 4.6% of which were due to periodontitis. Most patients with TLP had ≥1 site with RPc ≥5 mm (90.8%) or ≥6 mm (77.6%). Multivariate multilevel Cox regression revealed that patients with >15% of sites with RPc ≥5 mm had a hazard ratio of 2.34, and grade C had a hazard ratio of 4.6 for TLP compared to RPc ≤4 mm/grade A. Grading exhibited the best discrimination and model fit. CONCLUSION: Patients with RPc ≥5 mm at >15% of the sites are at risk for tooth loss. Grading and RPc ≥5 mm displayed very good predictive capability of TLP.

The "Iceberg" Connective Tissue Graft Technique for Peri-implant Papilla Augmentation Following Interproximal Bone Reconstruction.

Implants with deficient papillae and black triangle are common findings. The treatment of these esthetic complications is considered challenging, and with limited predictability. Therefore, the aim of the present report is to describe a novel technique for papilla augmentation (the "Iceberg" connective tissue graft [iCTG]) after extraction and interproximal bone reconstruction in the anterior region. A 35-year-old patient presented with a hopeless tooth with interproximal clinical attachment loss extending up the apical third of the adjacent tooth. Interproximal bone reconstruction was performed through alveolar ridge preservation by directly applying recombinant human platelet-derived growth factor-BB (rhPDGF-BB) to the exposed root surface of the adjacent tooth. A mixture of autogenous bone chips (obtained from the ramus) and bovine bone xenograft particles, previously mixed with the growth factor, was also used. The patient was able to come back for implant therapy only 2 years later. An incomplete regeneration of the interproximal bone was observed. Therefore, to compensate the interproximal deficiency, the iCTG approach, involving a double layer CTG with different origins, was utilized. Two small grafts from the tuberosity were sutured to the mesial and distal ends of a wider CTG harvested from the palate, aiming at gaining additional volume at the interproximal sites. The composite graft was then sutured on top of the implant platform, with the flap that was then released and closed by primary intention. After conditioning of the peri-implant tissues, the case was finalized with a satisfactory outcome. The described iCTG could be an effective approach for reconstructing peri-implant papilla following interproximal bone reconstruction.

Facial Mucosal Level Change Following Maxillary Anterior Single Immediate Tooth Replacement in Extraction Sockets With Facial Bone Wall Defects: A 4- to 15-Year Retrospective Study.

An intact extraction socket has been considered a prerequisite for an immediate implant placement and provisionalization (IIPP) procedure. Recent studies, however, have shown successful outcomes when IIPP was performed in sockets with a facial bone wall defect. This retrospective study evaluated the facial implant mucosal stability following IIPP in extraction sockets with a facial bone wall defect in the esthetic zone. The study included 16 cases in 16 patients who received maxillary anterior single IIPP with contour bone graft (C-BG) and contour connective tissue graft (C-CTG) in compromised extraction sockets (V- or U-shaped defect). After a mean follow-up of 6 years, the implant success rate was 100% (16/16). Minimal and non-statistically significant changes were noted in the facial implant mucosal and marginal bone level. Statistically significant changes were observed in facial implant mucosal thickness gain (2.5 mm [1.8 mm to 3.5 mm]) and midfacial bone sounding reduction (6 mm). Within the confines of this study, IIPP with simultaneous C-BG and C-CTG in fresh extraction sockets exhibiting a V- or U-shaped facial bone wall defect can lead to long-term successful outcomes in terms of mucosal stability, contour bone gain, and marginal bone level stability.

Hard- and Soft-Tissue Reconstruction in the Anterior Maxilla for Esthetic Implant Therapy.

Implant rehabilitation in the esthetic zone is often challenged by vertical bone defects and soft-tissue deformities. This article describes a combined hard- and soft-tissue restorative approach that involves staged guided bone regeneration, implant placement, and two soft-tissue augmentation procedures to achieve optimal esthetic outcomes at multiple implant sites in the anterior zone. The staged bone augmentation procedure, performed with a mixture of autogenous and xenogeneic bone graft and a nonresorbable membrane, allowed for the placement of three implants in ideal positions after 9 months. Further soft-tissue augmentation involved the use of multiple connective tissue grafts (CTGs) stabilized on the occlusal aspect of the implants and between the implants to enhance peri-implant papillae (ie, the "iceberg" CTG approach). Then, a second soft-tissue grafting procedure was executed to reposition the mucogingival junction and re-establish an adequate amount of keratinized mucosa at the implant sites. The article highlights the importance of performing both hard- and soft-tissue augmentation for implant therapy in the esthetic zone.

Alveolar Ridge Preservation and Restoration with Titanium-Reinforced d-PTFE Membranes and Bone Substitutes of Severely Resorbed Sockets: A Pilot Case Series Study.

This pilot case series study reports the dimensional alveolar bone changes after reconstruction of severely resorbed postextraction sockets treated with a mixture of particulate bone allograft and xenograft in combination with titanium-reinforced dense polytetrafluoroethylene (Ti-d-PTFE) membranes. Ten subjects who required premolar or molar extraction were included. Bone grafts were protected with Ti-d-PTFE membranes, utilizing an open-healing environment; membranes were removed 4 to 6 weeks after extraction, and implants were placed 6.7 months (mean) after extraction (T1). One patient required additional augmentation to correct an apical undercut of the alveolar process that was present preextraction. All implants integrated well and showed an implant stability quotient (ISQ) value between 71 and 83. The mean horizontal ridge width reduction from baseline (extraction) to T1 was 0.8 mm. Throughout the study, the mean vertical bone gain increase ranged from 0.2 mm to 2.8 mm (mean keratinized tissue width increase: 5.8 mm). The ridge preservation/restoration technique showed good preservation and restoration of severely resorbed sockets as well as improved amounts of keratinized tissue. If implant therapy is required after tooth extraction and severely resorbed sockets are present, the use of a Ti-d-PTFE membrane is a realistic option.

Complications and treatment errors in peri-implant hard tissue management.

Bone augmentation procedures aim to regenerate the deficient alveolar ridge to properly place dental implants that are completely surrounded by bone. However, these are invasive and technically demanding surgeries that are not free of either complications or treatment errors. Careful patient selection and preparation is a mandatory process to reduce the rate of complications in bone regeneration procedures, irrespective of the technique used. It is important to assess the cost benefit of the intervention and to evaluate the potential impact on the patient's quality of life, especially in the elderly and medically compromised patients. Most common postoperative complications are wound dehiscences, which may be reduced, at least partially, by proper knowledge of the surgical technique and the craniofacial anatomy. Other complications that may appear are postoperative infections or nerve injuries. The aim of this narrative review is to summarize the best available scientific evidence on the incidence of complications, as well as the ideal strategies for their prevention and management. Depending on the severity of the complication, treatment approaches may vary and can include drug prescription or even surgical re-entries to remove exposed barrier membranes or contaminated bone grafts. Adequate prevention and proper management of complications associated with bone augmentation interventions are a requirement for clinicians carrying out these demanding procedures. A series of cases illustrating proper management of complications in different clinical scenarios is presented.

Papilla reconstruction using a vertical interproximal tunnel approach.

INTRODUCTION: Papilla reformation is one of the most difficult and elusive surgical techniques for clinicians. Although it involves similar tenets to those applied for soft tissue grafting at recession defects, crafting a small tissue in restricted space remains unpredictable. Numerous grafting techniques have been developed to correct interproximal and buccal recession, but so far, only a limited number of techniques have been prescribed for interproximal remediation. CASE PRESENTATION: This report describes in detail a modern technique (the vertical interproximal tunnel approach) for reforming the interproximal papilla and treating interproximal recession. It also documents three challenging cases of papilla loss. The first case presented Class II papilla loss and a recession type 3 gingival defect adjacent to a dental implant, managed using the vertical interproximal tunnel approach through a short vertical incision. A 6-mm increase in attachment level and almost complete papilla fill were observed in this case with this surgical technique for papilla reconstruction. The second and third cases presented Class II papilla loss between two adjacent teeth, managed using the vertical interproximal tunnel approach through a semilunar incision and achieving full papilla reconstruction. CONCLUSION: Both described incision designs for the vertical interproximal tunnel approach require technical meticulousness. When executed carefully and using the most beneficial pattern of blood supply, predictable reconstruction of the interproximal papilla can be achieved. It also helps alleviate concerns associated with inadequate flap thickness, blood supply and flap retraction.

Techniques on vertical ridge augmentation: Indications and effectiveness.

Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness.

Minimal invasiveness in vertical ridge augmentation.

Vertical ridge augmentation is one of the most challenging procedures in implant dentistry because of the advanced skills required by the operator and the fact that bone augmentation is aimed outside the bony contour, in an environment of reduced blood supply. What is more, the flap management required to ensure soft tissue closure frequently leads to associated comorbidities in terms of swelling and hematomas. For these reasons, and even if autologous onlay block grafts are still the gold standard, new techniques and biomaterials have favored the development of potentially less invasive approaches. The present work evaluates the most recent strategies in vertical ridge augmentation to reduce invasiveness and complications, including diagnostic/treatment planning considerations, surgical techniques, digital tools (eg, customized titanium meshes/membranes or bone blocks), and future trends in the field of tissue engineering and cell therapy.

Facial implant gingival level and thickness changes following maxillary anterior immediate tooth replacement with scarf-connective tissue graft: A 4-13-year retrospective study.

OBJECTIVE: A scarf-shaped connective tissue graft can be placed at the facial and proximal aspect of the peri-implant soft tissue zone during immediate implant placement and provisionalization (IIPP) procedures in the esthetic zone to optimize implant esthetics without the need of flap reflection. This retrospective study evaluated soft tissue stability after scarf-connective tissue graft (S-CTG) in conjunction with IIPP procedures in the esthetic zone. MATERIALS AND METHODS: Patients who received IIPP with S-CTG with a minimum 1-year follow-up were evaluated. Mid-facial gingival level (MFGL) change and mid-facial gingival thickness (MFGT) change were measured and compared at the pre-op (T0), IIPP + S-CTG surgery (T1), follow up appointment with MFGT measurement (T2), and latest follow-up appointment (T3). Implant success rate and graft necrosis were also recorded. RESULTS: A total of 22 IIPP and S-CTG procedures in 20 patients were evaluated in the study. After a mean follow-up of 8.2 years (3.9-13.4) (T3), all implants remained osseointegrated (22/22 [100%]), with statistically insignificant mean midfacial gingival level change of -0.19 mm (-1.5 to 0.8). Statistically significant difference in midfacial gingival thickness (MFGT) was noted (2.5 mm [1.8-3.5 mm]) after a mean follow-up time (T2) of 2.3 years (1-8.6) when compared with MFGT at baseline (1.1 mm [0.6-1.3 mm]) (T1). Necrosis of S-CTG during initial healing phase was noted in 9% (2/22) of the sites. CONCLUSIONS: Within the confines of this study, scarf-connective tissue graft at time of immediate implant placement and provisionalization can thicken the gingiva and maintain the gingival level at the critical soft tissue zone. CLINICAL SIGNIFICANCE: Managing the soft tissue zone is as important as that of the hard tissue zone for peri-implant esthetics. Connective tissue graft is one of the methods that can enhance the final esthetic outcomes. This retrospective study has demonstrated that Scarf-CTG technique is an effective treatment modality to maintain soft tissue stability.

Guided bone regeneration in implant dentistry: Basic principle, progress over 35 years, and recent research activities.

Bone augmentation procedures are frequent today in implant patients, since an implant should be circumferentially anchored in bone at completion of bone healing to have a good long-term stability. The best documented surgical technique to achieve this goal is guided bone regeneration (GBR) utilizing barrier membranes in combination with bone fillers. This clinical review paper reflects 35 years of development and progress with GBR. In the 1990s, GBR was developed by defining the indications for GBR, examining various barrier membranes, bone grafts, and bone substitutes. Complications were identified and reduced by modifications of the surgical technique. Today, the selection criteria for various surgical approaches are much better understood, in particular, in post-extraction implant placement. In the majority of patients, biodegradable collagen membranes are used, mainly for horizontal bone augmentation, whereas bioinert PTFE membranes are preferred for vertical ridge augmentation. The leading surgeons are using a composite graft with autogenous bone chips to accelerate bone formation, in combination with a low-substitution bone filer to better maintain the augmented bone volume over time. In addition, major efforts have been made since the millenium change to reduce surgical trauma and patient morbidity as much as possible. At the end, some open questions related to GBR are discussed.

Periosteum Classification and Flap Advancement Techniques Around the Mental Foramen.

Various surgical flap advancement techniques for bone regeneration have been described in the literature; however, the clinical challenges of managing tissue that contains scars or embedded foreign materials have not been thoroughly described, especially around metal foramen. Fibrotic and thickened scar periosteum as well as mental foramen restrict the tissue from responding in the same way as native tissue. Therefore, additional considerations and approaches must be considered to achieve tension-free flap closure. This article presents a flap advancement classification that describes three common clinical scenarios based on the periosteum and soft tissue quality and provides surgical approaches for tissue management in each classification, with a focus on flap advancement around the mental foramen.

Radiographic protrusion of dental implants in the maxillary sinus and nasal fossae: A multidisciplinary consensus utilising the modified Delphi method.

The aim of the present study was to generate an international and multidisciplinary consensus on the clinical management of implant protrusion into the maxillary sinuses and nasal fossae. A total of 31 experts participated, 23 of whom were experts in implantology (periodontologists, maxillofacial surgeons and implantologists), 6 were otolaryngologists and 2 were radiologists. All the participants were informed of the current scientific knowledge on the topic based on a systematic search of the literature. A list of statements was created and divided into three surveys: one for all participants, one for implant providers and radiologists and one for otolaryngologists and radiologists. A consensus was reached on 15 out of 17 statements. According to the participants, osseointegrated implants protruding radiographically into the maxillary sinus or nasal fossae require as much monitoring and maintenance as implants fully covered by bone. In the event of symptoms of sinusitis, collaboration between implant providers and otolaryngologists is required. Implant removal should be considered only after pharmacological and surgical management of sinusitis have failed.